function toggle_visibility(id){
       var which = document.getElementById(id);
	if (!document.getElementById)
	return;
	if (which.style.display==""){
	which.style.display="none";
	return;
	}
	if (which.style.display=="block")
	which.style.display="none";
	else
	which.style.display="block";
}

function showid(id){
       var which = document.getElementById(id);
	which.style.display="block";
}

function hideid(id){
       var which = document.getElementById(id);
	which.style.display="none";
}